• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Master's Dissertation
DOI
10.11606/D.10.2004.tde-16062004-145626
Document
Author
Full name
Laura Yaneth Villarreal Buitrago
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2003
Supervisor
Committee
Ferreira, Antônio José Piantino (President)
Baccaro, Maria Regina
Lima, Carlos Henrique de Azeredo
Title in Portuguese
Coronavirus em aves: detecção, caracterização molecular e filogenética e inoculação experimental em aves SPF
Keywords in Portuguese
aves
coronavírus
diarréia
inoculação
transmissão
virologia
Abstract in Portuguese
Em uma unidade produtora de matrizes pesadas, localizada no Estado de São Paulo, foram colhidas duas amostras de conteúdo intestinal de aves com duas semanas de idade, quatro amostras de fezes da cama do mesmo lote às 18 semanas e uma amostra da cama às 30 semanas para pesquisa de coronavirus por uma técnica de nested RT-PCR dirigida a um segmento do gene codificador da RNA–polimerase RNA-dependente (gene pol). Destas, foram positivas 6 amostras correspondentes às duas aves de duas semanas, 3 às aves com 18 semanas e 1 às aves com 30 semanas. A análise filogenética da seqüência do c-DNA correspondente a uma das amostras das aves de duas semanas agrupou este vírus entre os coronavirus do grupo 2. Quando inoculado pelas vias ocular e oral em aves White Leghorn SPF, evidenciou-se diarréia moderada, despigmentação e atraso no crescimento. Os exames anátomo e histopatológicos dos órgãos colhidos revelaram predominantemente enterite e atrofia de vilosidades no reto e duodeno, com infiltração de células mononucleares e exposição de lâmina própria. Aves sentinela SPF alocadas entre os grupos inoculados apresentaram os mesmos sinais clínicos e achados anátomo e histopatógicos. O coronavírus inoculado foi evidenciado em todos os grupos experimentais em intestino delgado, reto, pâncreas e pulmão, assim como em conteúdo entérico. Seqüenciamento e analise filogenética foram realizados com uma amostra positiva por PCR em cada um dos grupos experimentais, confirmando a identidade entres os vírus recuperados e o vírus inoculado e a proximidade deste vírus com os coronavirus do grupo 2, considerando-se o fragmento estudado. Estes resultados demonstram que o coronavirus encontrado, causa doença entérica nas aves, com tropismo predominante por reto e intestino delgado, transmitindo-se horizontalmente de modo eficiente poucas horas após a inoculação e que o segmento do gene pol estudado aproxima este vírus dos coronavirus do grupo 2.
Title in English
Avian coronaviruses: detection, molecular and phylogenetic characterization and experimental inoculation in SPF birds
Keywords in English
birds
coronavirus
diarrhea
inoculation
transmission
virology
Abstract in English
In a broiler breeder farm located at São Paulo State two samples of intestinal contents of 2-week old birds, four fecal samples of the floor from the same flock at 18 weeks of age and one at 30 weeks of age were surveyed to coronavirus by a nested RT-PCR assay targeted to the RNA-dependent RNA-polymerase gene (pol gene). Six out of these samples were positive, two of which from the 2-week old birds, 3 from the 18-week old birds and 1 from the 30-week old birds. Phylogenetic analysis of the c-DNA sequence from one positive sample of a 2-week old bird showed that the virus clustered among group 2 coronaviruses. Oral and ocular inoculation of White Leghorn SPF birds with this coronavirus led to mild diarrhea, depigmentation and growth delay. Gross and histopatological examinations of collected tissues showed enteritis and atrophy of the villi on the small gut and rectum with mononuclear cells infiltration and exposition of the lamina propria. SPF sentinel birds placed between inoculated groups showed the same clinical signs and gross and histological findings. The inoculated coronavirus was evidenced in all experimental groups in the small gut, rectum, pancreas and lungs and also in intestinal contents. DNA sequencing and phylogenetic analysis was carried out with one positive sample per group, confirming the identity between the recovered viruses and the close relationship between this virus and group 2 coronaviruses taking into account the studied fragment. These results show that the coronavirus here found causes enteric disease in birds, with a predominant tropism by the rectum and the small gut, being horizontally transmitted in a few hours and that the pol gene studied segment bring this virus close to group 2 coronaviruses.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
laurabuitrago.pdf (1.31 Mbytes)
Publishing Date
2004-12-03
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.